가문비나무로 제조된 직교형적층재의 동적탄성계수에 미치는 연륜경각의 영향
Effect of Annual Ring Angles on Dynamic Modulus of Elasticity of Cross-Laminated Woods Made With Spruce
1
조회
0
다운로드
1
인용
0
참고문헌
키워드
초록
이 연구에서는 목재의 효율적인 이용과 그 이용확대를 목적으로, 가문비나무를 이용한 직교형 적층재를 제작하였고, 동적탄성계수에 미치는 섬유직각방향라미나의 연륜경각의 영향을 조사하였다. 또한, 동적탄성계수로부터 정적 휨 강도성능을 예측하였다. 3층 모두가 섬유직각방향라미나로 구성된 평행형적층재(P⊥타입)의 동적탄성계수는 연륜경각의 영향이 현저히 나타났고, 연륜경각90∘에서 가장 높은 값을 나타내었고, 45∘에서 가장 낮은 값을 나타내었다. 중층에 섬유방향라미나를 배열하는 것에 의해 동적탄성계수는 현저히 향상되었다. 표층에 섬유직각방향라미나로 구성된 직교형 적층재 (C⊥타입)의 경우, 동적탄성계수는 연륜경각 90∘>0∘>45∘의 순이었으나, 연륜경각에 의한 차이는 평행형 적층재에 비해 현저히 감소하였다. 중층에 섬유직각방향라미나를 배열한 직교형 적층재 (C∥ 타입)의 경우, 동적탄성계수는 P⊥타입 및 C⊥타입과 역으로 연륜경각 45∘에서 가장 높은 값을 나타내었고, 그 값은 P∥ 타입보다 약간 적은 값을 나타내는 것이 확인되었다. 동적탄성계수와 정적 휨강도성능과의 상관회귀의 결과로부터 평행형 및 직교형 적층재의 정적 휨 강도성능이 동적탄성계수로부터 예측 가능한 것이 확인되었다. 단 C⊥타입의 경우, 충분한 시험편의 개수로 상관회귀를 실시할 필요가 있었다.
Abstract
To study an effective use and extension of utilization of woods, cross-laminated woods were made with spruce wood, and the effects of annual ring angles of perpendicular direction laminae on dynamic modulus of elasticity (MOE) were investigated, and static bending strength performances were estimated from dynamic MOE. Dynamic MOE of parallel laminated woods with all layers composed of laminae perpendicular to the grain (P⊥ type) depended much on annual ring angles, and it was highest in 90∘ annual ring angle, and was lowest in 45∘ annual ring angle. By placing longitudinal-direction laminae in the core, the dynamic MOE was markedly improved. In the case of cross-laminated woods with perpendicular-direction laminae in the faces (C⊥ type), the dynamic MOE was in the order of 90∘> 0∘> 45∘, but the differences among annual ring angles were less than that of the parallel-laminated woods. In the case of cross-laminated woods with perpendicular-direction laminae in the core (C∥ type), the dynamic MOE showed the highest value in 45∘ annual ring angle inversely from P⊥ type and C⊥ type. From the results of regression analyses between dynamic MOE and static strength performances, it was found that static bending strength performances can be estimated from the dynamic MOE.
참고문헌 (15)
- Ayarkwa, J., "Predicting modulus of rupture of solid and finger-jointed tropical African hardwoods using longitudinal vibration", Forest Prod. J, 51(1), pp.85~92 (2001)
- Bender, D. A., "Predicting localized MOE and tensile strength in solid and finger-jointed laminating lumber using longitudinal stress waves", Forest Prod. J, 40(3), pp.45~47 (1990)
- Byeon, H. S., "Nondestructive evaluation of strength performance for finger-jointed woods using flexural vibration techniques", Forest Prod. J, 55(10), pp.37~42 (2005)
- Cha, J. K, "Study on stress waves for development of glulam from domestic small diameter log(1)", Mokchae Konghak, 24(3), pp.90~100 (1996)
- Hong, B. H, "The dynamic mechanical properties of paulownia coreana used for sounding boards", Mokchae Konghak, 13(3), pp.34~40 (1985)
- Jang, S. S., "Evaluation of lumber properties by applying stress waves to larch logs grown in Korea", Forest Prod. J, 50(3), pp.44~48 (2000)
- Kataoka, A., "The relations of experimental factors to the vibration and the measuring values of dynamic mechanical properties of wood Ⅰ. The experimental errors due to the measuring apparatus", Mokuzai Gakkaishi, 21(10), pp.543~550 (1975)
- Kataoka, A., "The dynamic mechanical properties of sitka spruce used for sounding boards", Mokuzai Gakkaishi, 22(8), pp.436~443 (1976)
- Lee, D. S., "Evaluation of static bending properties for some domestic softwoods and tropical hardwoods using sonic stress wave measurements", Mokchae Konghak, 25(1), pp.8~14 (1997)
- Matsumoto T., "Elastic properties of plywood in dynamic test Ⅰ. Relation between static Young’s modulus and dynamic Young’s modulus", Mokuzai Gakkaishi, 14(2), pp.65~69 (1968)
- Norimoto, M, "Structure and properties of wood used for musical instruments Ⅰ", Mokuzai Gakkaishi, 28(7), pp.407~413 (1982)
- 박한민, "Effect of Finger Profile on Static Bending Strength Performance of Finger-jointed Wood", 목재공학, 32(6), pp.57~66 (2004), 한국목재공학회
- Sobue, N., "Vibrational properties of spruce plywood for musical instruments", Mokuzai Gakkaishi, 31(1), pp.93~97 (1984)
- Sung, E. J., "Effect of Annual Ring Angles on Static Bending Strength Performances of Cross-Laminated Woods Made With Spruce" (2013), Mokchae Konghak
- Tonosaki, M., "Vibration properties of sitka spruce with longitudinal vibration and flexural vibration", Mokuzai Gakkaishi, 29(9), pp.547~552 (1983)